Another result further underscores general public discontent and sounds a cautionary note for the Republicans in the midst of their victory. Just 43 percent of voters expressed a favorable opinion of the in-power Democratic Party, vs. 52 percent who saw it negatively. But on the Republican Party, it was essentially the same -- 41 percent favorable, 53 percent unfavorable.
The Republicans relied on differential turnout. Among Tuesday's voters, 46 percent voted for Obama in 2008, 45 percent for John McCain -- an election Obama won by 53-45 percent. Thirteen percent of Obama voters defected to Republicans for Congress, while 8 percent of McCain voters favored Democrats. And among other voters -- the 8 percent who either didn't vote, or voted for someone else, in 2008 -- Republicans won by 57-36 percent.
GOP candidates scored better than they have in decades among some key demographic groups. Consider:
Women voted 49-48 percent for Democratic vs. Republican House candidate -- the best for Republicans among women in national House vote in exit polls since 1982. Obama won women by 13 points in 2008.
Democrats and Republicans were at parity in self-identification nationally, 36-36 percent, a return to the close division seen in years before 2008, when it broke dramatically in the Democrats' favor, 40-33 percent.
Swing-voting independents who, as usual, made the difference, favored Republicans for House by a thumping 16 points, 55-39 percent. Compare that to Obama's 8-point win among independents in 2008. It was the Republicans' biggest win among independents in exit polls dating to 1982 (by two points. The GOP won independents by 14 points in 1994, the last time they took control of the House.)
Sixty percent of whites backed Republican House candidates, the most in exit polls dating back to 1982. (In presidential rather than House vote Ronald Reagan won more whites in 1984).
Conservatives accounted for 41 percent of voters -- a high in recent exit polls exceeded, in available data, only by 43 percent in that Reagan re-election of 1984.
It also was the biggest vote for Republicans among white Catholics -- like independents, a true swing voter group. They voted 40-58 in favor of Republicans for House. In the next widest, in 1994, Republicans won white Catholics by 55-44 percent.
Seniors accounted for 23 percent of the vote, their highest in national House vote in data back to 1992, and their 18-point margin in support of Republican candidates, was the best such margin among seniors in House vote for the GOP, in available exit poll data since 1992.
Regionally, the South went hugely for Republican House candidates, 58-39 percent, the best GOP advantage in the South in exit polls since 1990. And Republicans ran +9 in the Midwest, their best since their +9 in 1994.
In 2008, working-class white men and women (those who make <$50,000) split about evenly in their House vote. Tuesday they favored the Republican candidate -- men by a double-digit margin, 55-42 percent; women by 8 points, 52-44 percent.
One widely discussed effect of public disenchantment this year has been the rise of the Tea Party political movement. Forty percent of voters described themselves as supporters of the Tea Party (21 percent supported it strongly) and they voted by an overwhelming 86-11 percent for Republican House candidates. Thirty-one percent opposed the movement and voted 86-12 for Democrats; the rest, 25 percent, were "neutral" about it and split about evenly.